High flow therapy device utilizing a non-sealing respiratory interface and related methods

ABSTRACT

A high flow therapy system for delivering heated and humidified respiratory gas to an airway of a patient includes a respiratory gas flow pathway for delivering the respiratory gas to the airway of the patient by way of a non-sealing respiratory interface; wherein flow rate of the respiratory gas is controlled by a microprocessor, a mixing area for mixing a first gas and a second gas in the respiratory gas flow pathway, a humidification area downstream of the mixing area and configured for humidifying respiratory gas in the respiratory gas flow pathway, and a heated delivery conduit for minimizing condensation of humidified respiratory gas.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 17/387,505, filed on Jul. 28, 2021, now U.S. Pat.No. 11,406,777, which is a continuation application of U.S. patentapplication Ser. No. 15/250,834, filed on Aug. 29, 2016, which is acontinuation application of U.S. patent application Ser. No. 13/717,442,filed on Dec. 17, 2012, now U.S. Pat. No. 9,427,547, which is acontinuation application of U.S. patent application Ser. No. 11/638,981,filed on Dec. 14, 2006, now U.S. Pat. No. 8,333,194, which is acontinuation-in-part application of U.S. patent application Ser. No.11/520,490, filed on Sep. 12, 2006, which claims the benefit of U.S.Provisional Patent Application Ser. No. 60/716,776, filed Sep. 12, 2005.The present application also claims the benefit and priority of U.S.Provisional Patent Application Ser. No. 60/750,063, filed on Dec. 14,2005; U.S. Provisional Patent Application Ser. No. 60/792,711, filed onApr. 18, 2006; and U.S. Provisional Patent Application Ser. No.60/852,851, filed on Oct. 18, 2006. The entire contents of each of theseapplications are hereby incorporated by reference herein.

BACKGROUND

Respiratory interfaces, e.g., nasal cannulas are used to deliverrespiratory gases for therapeutic effect, including oxygen therapy,treatment for sleep apnea, and respiratory support. Small nasal cannulasare commonly used for delivery of low volumes of oxygen. Sealing nasalcannulas, such as the cannulas disclosed in U.S. Pat. No. 6,595,215 toWood, are used for the treatment of sleep apnea. However, treatment withcertain types of nasal cannulas may be limited by the lack ofinformation available on important treatment parameters. Theseparameters include information regarding the gases within the user'supper airway, such as pressure, flow rate, and carbon dioxide build up.These and other data may be useful in judging the efficacy of treatmentas well as for controlling and monitoring treatment.

In addition, prior art nasal cannula designs (especially those designedfor neonatal oxygen therapy) may undesirably create a seal with theuser's nares, which may have detrimental effects on the user's health.

Oxygen (0₂) therapy is often used to assist and supplement patients whohave respiratory impairments that respond to supplemental oxygen forrecovery, healing and also to sustain daily activity.

Nasal cannulas are generally used during oxygen therapy. This method oftherapy typically provides an air/gas mixture including about 24% toabout 35% 0₂ at flow rates of 1-6 liters per minute (L/min). At aroundtwo liters per minute, the patient will have a FiO₂ (percent oxygen inthe inhaled O₂/air mixture) of about 28% oxygen. This rate may beincrease somewhat to about 8 L/min if the gas is passed through ahumidifier at room temperature via a nasal interface into the patient'snose. This is generally adequate for many people whose conditionresponds to about 35-40% inhaled 0₂ (FiO₂), but for higherconcentrations of 0₂, higher flow rates are generally needed.

When a higher FiO₂ is needed, one cannot simply increase the flow rate.This is true because breathing I 00% 0₂ at room temperature via a nasalcannula is irritating to the nasal passage and is generally nottolerated above about 7-8 L/min. Simply increasing the flow rate mayalso provoke bronchospasm.

To administer FiO₂ of about 40% to about I 00%, non-re-breathing masks(or sealed masks) are used at higher flows. The mask seals on the faceand has a reservoir bag to collect the flow of oxygen during theexhalation phase and utilize one-way directional valves to directexhalation out into the room and inhalation from the oxygen reservoirbag. This method is mostly employed in emergency situations and isgenerally not tolerated well for extended therapy.

High flow nasal airway respiratory support (“high flow therapy” or“HFT”) is administered through a nasal cannula into an “open” nasalairway. The airway pressures are generally lower than ContinuousPositive Airway Pressure (CPAP) and Bi-level Positive Airway Pressure(BiPAP) and are not monitored or controlled. The effects of such highflow therapies are reported as therapeutic and embraced by someclinicians while questioned by others because it involves unknownfactors and arbitrary administration techniques. In such procedures, thepressures generated in the patients' airways are typically variable,affected by cannula size, nare size, flow rate, and breathing rate, forinstance. It is generally known that airway pressures affect oxygensaturation, thus these variables are enough to keep many physicians fromutilizing HFT.

SUMMARY

The present disclosure relates to a high flow therapy system fordelivering heated and humidified respiratory gas to an airway of apatient includes a respiratory gas flow pathway for delivering therespiratory gas to the airway of the patient by way of a non-sealingrespiratory interface; wherein flow rate of the respiratory gas iscontrolled by a microprocessor, a mixing area for mixing a first gas anda second gas in the respiratory gas flow pathway, a humidification areadownstream of the mixing area and configured for humidifying respiratorygas in the respiratory gas flow pathway, and a heated delivery conduitfor minimizing condensation of humidified respiratory gas. Anotheraspect of this embodiment provides for at least one of respiration rate,tidal volume and minute volume are calculated by the microprocessorusing data from the airway pressure sensor.

The present disclosure also relates to a method of supplying a patientwith gas. The method includes providing a high flow therapy deviceincluding a microprocessor, a heating element disposed in electricalcommunication with the microprocessor and capable of heating a liquid tocreate a gas, a non-sealing respiratory interface configured to deliverthe gas to a patient and a sensor disposed in electrical communicationwith the microprocessor and configured to measure pressure in the upperairway of the patient. This method also includes heating the gas anddelivering the gas to a patient.

The present disclosure also relates to a high flow therapy system fordelivering pressurized, heated and humidified respiratory gas to anairway of a patient includes a respiratory gas flow pathway fordelivering the pressurized respiratory gas to the airway of the patientby way of a non-sealing respiratory interface; where flow rate of thepressurized respiratory gas is controlled by a microprocessor, a mixingarea for mixing oxygen and air in the respiratory gas flow pathway, ahumidification area for humidifying respiratory gas in the respiratorygas flow pathway, a heated delivery conduit for minimizing condensationof humidified respiratory gas and a pressure pathway for monitoringpressure of the airway of the patient and communicating the monitoredpressure to the microprocessor, where the system is configured todetermine the respiratory phase of the patient.

The present disclosure also relates to a method of supplying a patientwith gas. The method including providing a high flow therapy device,heating a gas and delivering the gas to a patient. The high flow therapydevice of this method includes a heating element, a non-sealingrespiratory interface, a blower, an air inlet port and an air filter.The heating element is capable of heating a liquid to create a gas. Thenon-sealing respiratory interface is configured to deliver the gas to apatient. The blower is dispose din mechanical cooperation with thenon-sealing respiratory interface and is capable of advancing the gas atleast partially through the non-sealing respiratory interface. The airinlet port is configured to enable ambient air to flow towards to theblower. The air filter is disposed in mechanical cooperation with theair inlet port and is configured to remove particulates from the ambientair.

The present disclosure also relates to a method of treating a patientfor an ailment such as a headache, upper airway resistance syndrome,obstructive sleep apnea, hypopnea and snoring. The method includesproviding a high flow therapy device, heating a gas and delivering thegas to a patient. The high flow therapy device includes a heatingelement capable of heating a liquid to create a gas and a non-sealingrespiratory interface configured to deliver the gas to a patient.

The present disclosure also relates to a method of deliveringrespiratory gas to a patient. The method includes providing a high flowtherapy device, monitoring the respiratory phase of the patient andpressurizing the gas. The high flow therapy device of this methodincludes a heating element capable of heating a liquid to create a gas,a non-sealing respiratory interface configured to deliver the gas to apatient, and a sensor configured to measure pressure in the upper airwayof the patient.

The present disclosure also relates to a high flow therapy deviceincluding a microprocessor, a heating element, a non-sealing respiratoryinterface, a sensor and a mouthpiece. The heating element is disposed inelectrical communication with the microprocessor and is capable ofheating a liquid to create a gas. The non-sealing respiratory interfaceis configured to deliver the gas to a patient. The sensor is disposed inelectrical communication with the microprocessor and is configured tomeasure pressure in an upper airway of the patient. The mouthpiece isdisposed in mechanical cooperation with the sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the accompanying drawing figures, whichare not necessarily drawn to scale.

FIG. 1 is a perspective view of a nasal cannula according to aparticular embodiment of the invention.

FIG. 2 is a perspective view of a nasal cannula according to a furtherembodiment of the invention.

FIG. 3 is a perspective view of a nasal cannula according to anotherembodiment of the invention.

FIG. 4 is a perspective view of a nasal cannula according to yet anotherembodiment of the invention.

FIG. 5 is a front perspective view of a nasal cannula according to afurther embodiment of the invention.

FIG. 6 depicts a cross section of a nasal insert of a nasal cannulaaccording to a particular embodiment of the invention.

FIG. 7 depicts a cross section of a nasal insert of a nasal cannulaaccording to a further embodiment of the invention.

FIG. 8A is a front perspective view of a nasal cannula according toanother embodiment of the invention.

FIG. 8B is a rear perspective view of the nasal cannula shown in FIG.8A.

FIG. 8C is a perspective cross-sectional view of the nasal cannula shownin FIG. 8A.

FIG. 9 is a perspective view of a nasal cannula according to a furtherembodiment of the invention.

FIG. 10 is a perspective view of a nasal cannula according to anotherembodiment of the invention.

FIG. 11 is a perspective view of a nasal cannula according to a furtherembodiment of the invention.

FIG. 12 is a perspective view of a nasal cannula according to yetanother embodiment of the invention.

FIG. 13 illustrates an embodiment of a nasal cannula in use on apatient, according to one embodiment of the invention.

FIG. 14 illustrates another embodiment of a nasal cannula in use on apatient, according to a further embodiment of the invention.

FIG. 15 illustrates a perspective view of a high flow therapy device inaccordance with an embodiment of the present disclosure.

FIG. 16 illustrates a perspective view of the high flow therapy deviceof FIG. 15 showing internal components, in accordance with an embodimentof the present disclosure.

FIG. 17 illustrates a schematic view of the high flow therapy device ofFIGS. 15 and 16 with a nasal interface and a patient in accordance withan embodiment of the present disclosure.

FIG. 18 illustrates a high flow therapy device including a nasalinterface and a conduit in accordance with an embodiment of the presentdisclosure.

FIGS. 19 and 20 illustrate an enlarged view of a patient's upper airwayand a nasal interface in accordance with two embodiments of the presentdisclosure.

FIG. 21 illustrates an example of a screen shot of a user interface ofthe high flow therapy device of FIGS. 15-17 in accordance with anembodiment of the present disclosure.

FIGS. 22 and 23 illustrate examples of a non-sealing respiratoryinterface in the form of a mouthpiece in accordance with embodiments ofthe present disclosure.

FIG. 24 illustrates a mouthpiece of FIG. 22 or 23 in use on a patient inaccordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The present inventions now will be described with reference to theaccompanying drawings, in which some, but not all embodiments of theinventions are shown. Indeed, these inventions may be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will satisfy applicable legal requirements. Likenumbers refer to like elements throughout. For example, elements 130,230, 330, 430, 530, 830, and 930 are all nozzles according to variousembodiments of the invention.

Overview of Functionality

Nasal cannula according to various embodiments of the invention may beconfigured to deliver high-flow therapeutic gases to a patient's upperairway through the patient's nose. Such gases may include, for example,air, humidity, oxygen, therapeutic gases or a mixture of these, and maybe heated or unheated. In particular embodiments of the invention, thecannula may be useful for CPAP (continuous positive airway pressure)applications, which may be useful in the treatment of sleep apnea and inproviding respiratory support to patients (e.g., after abdominalsurgery), to alleviate snoring, or for other therapeutic uses.

Nasal cannula according to particular embodiments of the inventioninclude (or are adapted to facilitate the positioning of) one or moresensors adjacent or within one or more of the cannula's nasal inserts.Accordingly, the nasal cannula may be configured so that at least aportion of one or more sensors is in place in one or both of a user'snares when the nasal cannula is operably worn by the user. This may beparticularly helpful in evaluating the environment of the internalportion of the user's nose and/or the user's upper airway. As describedin greater detail below, in various embodiments of the invention, thecannula is adapted so that it will not create a seal with the patient'snares when the cannula is in use.

Nasal cannula according to other embodiments of the invention includenozzles. A nozzle may be a nasal insert that is inserted into the user'snares. Other nozzles are adapted to remain outside of a user's nareswhile the cannula is in use. Accordingly, the nozzles avoid sealing withthe patient's nares while the cannula is in use. In some embodiments,the nasal cannula include elongate extensions that are inserted into theuser's nares to detect pressure in one or both nares.

In certain embodiments of the invention, sensors are provided adjacentor within both of the nasal cannula's nozzles. In various otherembodiments, sensors are provided adjacent or within one or moreelongate extensions that extend into the user's nares. In variousembodiments, elongate extensions may be used in conjunction with nasalinserts or with nozzles. The use of sensors may be useful, for example,in monitoring environmental changes from one of the user's nares to theother. This information may be helpful, for example, in determining whenthe dominant flow of air changes from one of the user's nares to theother, which may affect the desired flow characteristics of therapy.Accordingly, data from each nare may provide information that may beuseful in establishing or modifying the user's treatment regimen.Further, multiple sensors may be used in various embodiments.

Overview of Exemplary Cannula Structures

A cannula 10 according to one embodiment of the invention is shown inFIG. 1 . As may be understood from this figure, in this embodiment, thecannula 10 includes a base portion 105, which is hollow, elongated, andtubular, that includes a central portion 110, a first end portion 115,and a second end portion 120. The first and second end portions 115, 120may be angled relative to the central portion 110 as shown in FIG. 1 .

In various embodiments of the invention, the cannula 10 includes a firsttubing inlet 117 adjacent the outer end of the first end portion 115,and a second tubing inlet 122 adjacent the second end portion 120 (inother embodiments, the cannula may include only one such inlet). Thecannula 10 further comprises a pair of hollow, elongated, tubularnozzles (e.g., nasal catheters), nozzles 125, 130, that extend outwardlyfrom the base portion 105 and that are in gaseous communication with thebase portion's interior. In various embodiments, the respective centralaxes of the nozzles 125, 130 are substantially parallel to each other,and are substantially perpendicular to the central axis of the centralportion 110 of the base portion 105.

In particular embodiments of the invention, the cannula defines at leastone conduit that is adapted to guide at least one sensor so that thesensor is introduced adjacent or into the interior of the cannula sothat, when the cannula is being operably worn by a user, the environmentbeing monitored by the at least one sensor reflects that of the internalportion of the user's nose and/or the user's upper airway. In variousembodiments of the invention, a user may temporarily insert the at leastone sensor into or through the conduit to determine correct settings forthe cannula system, and then may remove the sensor after the correctsettings have been achieved. In other embodiments, the at least onesensor may be left in place within the conduit for the purpose ofmonitoring data within (or adjacent) the cannula over time (e.g., forpurposes of controlling the user's therapy regimen). In a furtherembodiment, the at least one sensor may be positioned adjacent an outletof the conduit.

The at least one sensor may be connected (e.g., via electrical wires) toa computer and/or a microprocessor that is controlling the flow ofrespiratory gases into the cannula. The computer may use informationreceived from the at least one sensor to control this flow of gas and/orother properties of the system, or may issue an alarm if the informationsatisfies pre-determined criteria (e.g., if the information indicatespotentially dangerous conditions within the patient's airway or if thesystem fails to operate correctly).

As may be understood from FIGS. 8A-8C, in a particular embodiment of theinvention, at least one of the cannula's conduits 850 is defined by, andextends within, a side wall of the cannula 800. Alternatively, theconduit may be disposed within an interior passage defined by thecannula. For example, one or more of the conduits may be defined by atube that is attached immediately adjacent an interior surface of thecannula (e.g., adjacent an interior surface of the cannula's baseportion, or an interior surface of one of the cannula's nozzles). Thecannula's conduits are preferably adapted for: (1) receiving a flow ofgas at one or more inlets that are in communication with the conduit,and (2) guiding this flow of gas to an outlet in the cannula. In variousembodiments, one or more of the inlets is defined within an exteriorportion of one of the cannula's nozzles.

As may be understood from FIG. 1 , in various embodiments of theinvention, each of the cannula's conduit outlets 136, 141 is located atthe end of a respective elongate, substantially tubular, outlet member135, 140. For example, in the embodiment shown in FIG. 1 , the cannula10 includes a first outlet member 135 that is substantially parallel tothe cannula's first nozzle 125. In this embodiment, the first outletmember 135 and the first nozzle 125 may be positioned on opposite sidesof the base portion 105 as shown in FIG. 1 . Similarly, in a particularembodiment of the invention, the cannula 10 includes a second outletmember 140 that is substantially parallel to the cannula's second nasalinsert 130. The second outlet member 140 and second nozzle 130 are alsopreferably positioned on opposite sides of the base portion 105. Nozzles125, 130 also may have nozzle outlets 181, 182 respectively.

In various embodiments of the invention, a sensor (e.g., a pressure,temperature, or 0₂ sensor) is provided in communication or adjacent atleast one of (and preferably each of) the cannula's outlets 136, 141 andis used to measure the properties of gas from that outlet 136, 141. In afurther embodiment of the invention, accessory tubing is used to connecteach outlet 135, 140 with at least one corresponding sensor (and/or atleast one external monitoring device) that may, for example, be spacedapart from the cannula 10.

In yet another embodiment of the invention, one or more sensors areprovided within the conduit, and used to measure the properties of gasaccessed through the conduit. In this embodiment, information from eachsensor may be relayed to a control system outside the cannula via, forexample, an electrical wire that extends from the sensor and through theoutlet 135, 140 of the conduit in which the sensor is disposed.

In alternative embodiments of the invention, each of the cannula'sconduits may extend: (1) from the conduit inlets 152, 154; (2) through,or adjacent, a side wall of one of the nozzles 125, 130; (3) through, oradjacent, a side wall of the base portion 105; and (4) to an outlet 135,140 that is defined within, or disposed adjacent, the base portion 105.In one such embodiment, the conduit comprises a substantially tubularportion that is disposed adjacent an interior surface of the cannula'sbase portion.

As may be understood from FIG. 2 , in certain embodiments of theinvention, the cannula 200 includes at least one sensor 245 that isintegrated into an exterior portion of the cannula 200 (e.g., within arecess 223 formed within an exterior surface of one of the cannula'snozzles, nozzles 225, 230). In this embodiment, information from thesensor 245 may be relayed to a control system outside the cannula 200via an electrical wire 246 that extends from the sensor 245, through aconduit, and out an outlet 235, 240 in the conduit. In variousembodiments of the invention, the conduit extends through or adjacent aninterior portion of a sidewall of one of the nozzles 225, 230 and/orthrough or adjacent an interior portion of a sidewall of the baseportion 205. Nozzles 225, 230 also have nozzle outlets 281, 282respectively.

In particular embodiments of the invention, at least one sensor 245 isfixedly attached to the cannula 10 so that it may not be easily removedby a user. Also, in particular embodiments, at least one sensor 245 isdetachably connected adjacent the cannula 10 so that the sensor 245 maybe easily detached from (and, in certain embodiments, reattached to) thecannula 10.

The cannula 1000 includes a base portion 1005, which is hollow,elongated, and tubular, that includes a central portion 1010, a firstend portion 1015, and a second end portion 1020. The first and secondend portions 1015 and 1020 may be angled relative to the central portion1010, as shown in FIG. 10 . In various embodiments of the invention, thecannula 1000 includes a first tubing inlet 1017 adjacent the outer endof the first end portion 1015, and a second tubing inlet 1022 adjacentthe outer end of the second end portion 1020.

The cannula 1000 further comprises a pair of hollow, elongated, tubularnozzles (a first nozzle 1026 and a second nozzle 1031) that extendoutwardly from the base portion 1005. In various embodiments, therespective central axes of the nozzles 1026, 1031 are substantiallyparallel to each other and are substantially perpendicular to thecentral axis of the central portion 1010 of the base portion 1005. Invarious embodiments, the nozzles 1026, 1031 define passageways that arein gaseous communication with the interior of the base portion 1005. Inparticular embodiments of the invention, the first and second nozzles1026, 1031 are adapted to be positioned outside of a user's nares whilethe cannula is in use. In particular embodiments, the nozzles 1026, 1031each define a respective nozzle outlet. For example, the first nozzle1026 defines a first nozzle outlet 1083, and the second nozzle 1031defines a second nozzle outlet 1084. In various embodiments, when thecannula 1000 is operatively positioned adjacent a user's nares, each ofthe nozzle's outlets 1083, 1084 is positioned to direct a focused flowof gas into a corresponding one of the user's nares.

In alternative embodiments, such as the embodiment shown in FIG. 12 ,the cannula 1200 may include a single nozzle 1227 that defines apassageway that is in gaseous communication with an interior portion ofthe base portion 1205. As described in greater detail below, in variousembodiments, the nozzle 1227 extends outwardly from the base portion1205 and has an oblong, or elliptical, cross-section. In this and otherembodiments, the nozzle 1227 is shaped to deliver a focused flow of gassimultaneously into both of a user's nares when the cannula 1200 is inuse.

In various embodiments, the nasal cannula includes one or more elongateextensions that are adapted for insertion into one or more of the user'snares. For example, returning to the embodiment shown in FIG. 10 , thecannula 1000 may include multiple elongate extensions (for example afirst elongate extension 1070 and a second elongate extension 1072) thatare long enough to allow each of the elongate extensions 1070, 1702 tobe inserted into a respective one of the user's nares while the cannula1000 is in use. In embodiments, elongate extensions 1070, 1072 may haveconduit inlets 1052, 1053 respectively. In various embodiments, each ofthe elongate extensions 1070, 1072 may have a central axis that runssubstantially parallel to the central axis of a corresponding nozzle1026, 1031. For example, as can be understood from FIG. 10 , in certainembodiments, a first elongate extension 1070 has a central axis thatlies substantially parallel to and below the central axis of acorresponding first nozzle 1026, when the cannula is operativelypositioned adjacent a user's nares. Similarly, in various embodiments, asecond elongate extension 1072 has a central axis that liessubstantially parallel to and below the central axis of a correspondingsecond nozzle 1031, when the cannula 1000 is operatively positionedadjacent a user's nares. In various other embodiments, the elongateextensions may lie within, and extend outwardly from, theircorresponding nozzles 1070, 1072.

As a further example, FIG. 12 illustrates an exemplary cannula 1200having multiple elongate extensions (a first elongate extension 1270 anda second elongate extension 1272), which both lie substantially beyond asingle nozzle 1227 when the cannula 1200 is in an operative positionadjacent the user's nose. In some embodiments, the central axes of thefirst and second elongate extensions 1270, 1272, may be substantiallyparallel to the central axis of the nozzle 1227. Also, in variousembodiments, one or both of the elongate extensions 1270, 1272 may liewithin the nozzle 1227. In this and other embodiments, a distal end ofeach of the elongate extensions 1270, 1272 may extend beyond a distalend of the nozzle 1227. Elongate extensions 1270, 1272 may have conduitinlets 1252, 1253 respectively, while nozzle 1227 has a nozzle outlet1281.

As described above, in certain embodiments of the invention, the nasalcannula includes one or more sensors that are adapted to measure gasdata (e.g., gas pressure) within the user's nares while the cannula isin use. For example, the cannula 1000 shown in FIG. 10 may include asensor positioned adjacent the distal end of one or both of the firstand second elongate extensions 1070, 1072. In various embodiments, eachelongate extension may be adapted to: (1) support a sensor adjacent(e.g., at) the distal end of the elongate extension; and (2) support awire that is simultaneously connected to the sensor and a controlmechanism that is adapted to adjust the properties of gas flowingthrough the cannula 1000.

In other embodiments, the elongate extensions define conduits. Forexample, one or more sensor(s) may be positioned within the interior orexterior of the elongate extensions and information from the sensor(s)may be relayed to a control system via a wire extending through aconduit (for example, elongate extension conduit 1023 of FIG. 10 ) orpassages defined by each of the elongate extensions. In one embodiment,as shown, for example, in FIG. 10 , the elongate extension conduit 1023is shaped similarly to the base portion 1005, and lies substantiallybelow the base portion 1005 when the cannula 1000 is operatively in use.In various embodiments, the elongate extension conduit 1023 ispositioned within the base portion 1005 such that the first and secondelongate extensions 1070, 1072 lie within, and extend outwardly from,the respective first and second nozzles 1026, 1031.

In various embodiments, each elongate extension defines a respectivesensing conduit. For example, in certain embodiments, each sensingconduit is adapted to provide a passage that permits sensing or gaseouscommunication between a user's nares and a control system or otherdevice for measuring and adjusting the properties of the air. In thisand other embodiments, a sensor may be positioned at the control box tomeasure the properties (e.g., pressure) of air in the user's nares. Insome embodiments, the elongate extensions define a conduit that servesboth as an air passageway as well as a conduit for allowing a wire topass from a sensor positioned adjacent the distal tip of the elongateextension to the control system or other device.

Data Monitored by Sensors

In various embodiments of the invention, such as those described above,one or more sensors may be positioned to measure gas data within aninterior portion of one of the nasal cannula's conduits, or to measuregas data adjacent an exterior portion of the cannula. In suchembodiments, one or more sensors may be, for example, positionedadjacent an interior or exterior surface of the cannula. In certainembodiments of the invention, one or more of the cannula's sensors isadapted to monitor one or more of the following types of data within thecannula's conduits, or adjacent the cannula's exterior surface (e.g.,adjacent a side portion, or distal end of, one of the cannula'snozzles): (1) gas pressure; (2) gas flow rate; (3) carbon dioxidecontent; (4) temperature; (5) level; and/or (6) oxygen content.

Absolute vs. Relative Pressure Measurements

In various embodiments of the invention, the cannula may be configuredfor sensing absolute pressure within, or adjacent, a particular portionof the cannula. Similarly, in particular embodiments, the cannula may beconfigured to measure the difference between the pressures at twodifferent locations within the cannula. This may be done, for example,by providing two separate sensors (e.g., that are positioned indifferent locations within one of the cannula's conduits), or byproviding two physically distinct gas intake conduits, each of which isadapted for routing gas from a different location within the cannula.For example, in various embodiments of the invention shown in FIG. 1 ,the first conduit inlet 152 may be connected to a first conduit that isadapted for routing gas to a first sensor, and the second conduit inlet154 may be connected to a physically separate second conduit that isadapted for routing gas to a second pressure sensor. Information fromthe first and second sensors may then be used to calculate thedifference in pressure between the first and second inlets 152, 154.Alternatively, a differential pressure sensor may be used.

Suitable Sensors

Suitable sensors for use with various embodiments of the inventioninclude electronic and optical sensors. For example, suitable sensorsmay include: (1) Disposable MEM Piezoelectric sensors (e.g., from SilexMicrosensors); (2) light-based sensors such as a McCaul 0₂ sensor—seeU.S. Pat. No. 6,150,661 to McCaul; and (3) Micro-pressure sensors, suchas those currently available from Honeywell.

Non-Sealing Feature

As shown in FIG. 4 , in various embodiments of the invention, cannula400 has one or more nozzles 425, 430 that includes one or more recesses423 (e.g., grooves, semicircular recesses, or other indentations orconduits) that extend along a length of the nozzle's exterior surface.As may be understood from this figure, in various embodiments of theinvention, at least one of these recesses 423 is an elongate groove thatextends from adjacent a distal surface of the nozzle 425, 430 and pastthe midpoint between: (1) the nozzle's distal tip and (2) the portion ofthe nozzle 425, 430 that is immediately adjacent the nasal cannula'sbase portion 405. As may also be understood from this figure, in variousembodiments of the invention, each groove 423 extends substantiallyparallel to the central axis of its respective nozzle 425, 430. Nozzles425, 430 also have nozzle outlets 481, 482 respectively. As shown inFIG. 3 , in various embodiments of the invention, cannula 300 has one ormore nozzles 325, 330 that includes one or more recesses 323 that extendalong a portion of length of the nozzle's exterior surface. As may beunderstood from this figure, in various embodiments of the invention, atleast one of these recesses 323 is an elongate groove that extends fromadjacent a distal surface of the nozzle 325, 330 between: (1) thenozzle's distal tip and (2) the portion of the nozzle 325, 330 that isimmediately adjacent the nasal cannula's base portion 305. As may alsobe understood from this figure, in various embodiments of the invention,each groove 323 extends substantially parallel to the central axis ofits respective nozzle 325, 330. Nozzles 325, 330 also have nozzleoutlets 381, 382 respectively.

In particular embodiments of the invention, such as the embodiment shownin FIG. 4 , at least one of the nozzles 425, 430 is configured so thatwhen the nozzles 425, 430 are operatively positioned within a user'snares, the nozzles do not form an airtight seal with the user's nares.This may be due, for example, to the ability of air to flow adjacent theuser's nare through recesses 423 in the nozzles 425, 430 when the useris wearing the nasal cannula.

FIGS. 5-8 depict additional embodiments of the invention that areconfigured so that when the cannula's nasal inserts are operativelypositioned adjacent (e.g., partially within) the user's nares, the nasalinserts do not form a seal with the user's nares. For example, in theembodiment shown in FIG. 5 , illustrating cannula 500, at least one (andpreferably both) of the cannula's nasal inserts, nozzles 525, 530,comprise a nozzle body portion 555 (which may, for example, besubstantially tubular), and one or more flange portions 560, 561 thatare adapted to maintain a physical separation between an exterior sidesurface of the nozzle body portion 555 and a user's nare when the nozzle525, 530 is inserted into the user's nare.

For example, in the embodiment of the invention shown in FIG. 5 , eachof the nozzles 525, 530 includes nozzle body portion 555 and a pair ofco-facing, elongated flanges, flanges 560, 561, that each have asubstantially cross section. In this embodiment, these C shaped flanges560, 561 cooperate with a portion of the exterior of the nozzle bodyportion 555 to form a substantially U-shaped channel (which is oneexample of a “nasal lumen”) through which ambient air may flow to and/orfrom a user's nasal passages when the cannula 500 is operatively inplace within the user's nares. In this embodiment, when the nozzles 525,530 are properly in place within the user's nares, respiratory gas isfree to flow into the -user's nose through the nozzle body portion 555,and ambient air is free to flow into and out of the user's nose througha passage defined by: (1) the flanges 560, 561; (2) the exterior sidesurface of the nozzle body portion 555 that extends between the flanges560, 561; and (3) an interior portion of the user's nose. In variousembodiments, air may flow to and/or from a user's nose through thispassage when the cannula 500 is operatively in place within the user'snares. A pathway (e.g., a semicircular pathway) may be provided adjacentthe interior end of this U-shaped channel, which may act as a passagewayfor gas exhaled and inhaled through the U-shaped channel. Inembodiments, nozzles 525, 530 may have conduit inlets 552, 554, andcannula 500 may have conduit outlets 535, 540.

The general embodiment shown in FIG. 5 may have many differentstructural configurations. For example, as shown in FIG. 6 , whichdepicts a cross section of a nozzle according to a particular embodimentof the invention, the respiratory gas passageways of the nozzles 655 ofa cannula may be in the form of a tube having an irregular cross section(e.g., a substantially pie-piece-shaped cross section) rather than acircular cross section. Alternatively, as may be understood from FIG. 7, the respiratory gas passageways of the nozzles 755 of a cannula may bein the form of a tube having a substantially half-circular cross sectionrather than a circular cross section.

Similarly, as may be understood from FIGS. 6 and 7 , the shape and sizeof the cannula's flanges may vary from embodiment to embodiment. Forexample, in the embodiment shown in FIG. 6 , each of the flanges 660,661 has a relatively short, substantially C-shaped cross section and thedistal ends of flanges 660, 661 are spaced apart from each other to forma gap. As shown in FIG. 7 , in other embodiments, each of the flanges760, 761 may have a relatively long, substantially C-shaped crosssection and the distal ends of the flanges 760, 761 may be positionedimmediately adjacent each other.

As may be understood from FIG. 7 , in various embodiments of theinvention, a separation 763 (e.g., a slit, such as an angular slit) isprovided between the flanges 760, 761. This may allow the flanges 760,761 to move relative to each other and to thereby conform to the nare inwhich the nozzle is inserted. In other embodiments, the cross section ofthe nozzles is substantially as that shown in FIG. 7 , except that noseparation 763 is provided within the semi-circular flange portion.Accordingly, in this embodiment of the invention, a substantiallysemi-circular portion of the exterior of the air passageway cooperateswith a substantially semi-circular portion of the flange portion to forman exterior having a contiguous, substantially circular cross section.One such embodiment is shown in FIGS. 8A-8C.

As may be understood from FIGS. 8A-8C, in this embodiment, when thecannula 800 is in use, respiratory gas may flow into the user's nosethrough inspiratory passageways 881 that extend through each of thenozzles 825, 830. Inspiratory passageways 881 are in gaseouscommunication with the interior of base portion 805 as shown in FIG. 8C.An expiratory passageway 885 of substantially semi-circular crosssection extends between the distal end of each nozzle 825, 830 to asubstantially semicircular expiratory passageway outlet 865 definedwithin the cannula's base portion 805. In various embodiments, when thecannula 800 is in use, the user may exhale or both inhale and exhale gasthrough this expiratory passageway 885. As previously mentioned, thiscannula embodiment does not form a seal within the user's nares due tothe expiratory passageways 885, even if the nozzles 825, 830 tightly fitwithin the nares. In further embodiments, nozzles 825, 830 may haverecesses 823.

In certain embodiments, as discussed above, a conduit 850 is provided ineach of the nozzles 825, 830 (see FIG. 8C) and may have conduit inlets852, 854. Each of these conduits 850 may be adapted to facilitatemeasuring gas data by: (1) receiving gas from the interior of acorresponding expiratory passageway 885 and/or from adjacent theexterior of one of the nozzles 825, 830, and/or (2) guiding the gas outof a corresponding conduit outlet 835, 840 in the cannula 800. Asdiscussed above, one or more sensors may be disposed within, oradjacent, the conduit 850 and used to assess one or more attributes ofgas flowing through or adjacent the conduit 850.

It should be understood that the embodiments of the invention shown inFIGS. 4-8 and related embodiments may have utility with or without theuse of sensors or sensor conduits. It should also be understood that thevarious nozzles may be configured to be disposed in any appropriateorientation within the user's nares when the cannula is operablypositioned within the user's nares. For example, in one embodiment ofthe invention, the cannula may be positioned so that the cannula's nasallumen is immediately adjacent, or so that it faces anterior-laterallyaway from, the user's nasal spine.

Turning to yet another embodiment of the invention, as shown in FIG. 9 ,the cannula 900 may be adapted so that a conduit inlet 970, 972 for atleast one sensor (or the sensing conduit itself) is maintained adjacent,and spaced a pre-determined distance apart from, the distal end of arespective nozzle 925, 930. In this embodiment, the sensor (or conduitinlet) may be spaced apart from the rest of the cannula 900 adjacent oneof the nozzle outlet openings. In embodiments, cannula 900 may haveconduit outlets 935, 940.

As may be understood from FIG. 10 , in various embodiments, the firstand second nozzles 1026, 1031 of the nasal cannula are configured toremain outside of the user's nares while the cannula is in use. Forexample, the nozzles may be of a length such that, when the cannula isin use, the distal ends of the nozzles 1026, 1031 lie adjacent, butoutside, the user's nares. By preventing insertion of the nozzles 1026,1031 into the nares, sealing of the nares can be avoided. As may beunderstood from FIG. 13 , in various embodiments, when the nasal cannulais in an operative position adjacent the user's nares, an outlet portion(and distal end) of each nozzle 1326, 1331 is spaced apart from, andsubstantially in-line (e.g., substantially co-axial) with, acorresponding one of the patient's nares. In various embodiments, whenthe nasal cannula is operatively in use, the outlet of each nozzle isspaced apart from the patient's nares and each nozzle is positioned todirect a focused flow of gas into a particular respective one of theuser's nares.

Referring to FIG. 11 , cannula 1100 includes a base portion 1105, whichis hollow, elongated, and tubular, that includes a central portion 1110,a first end portion 1115, and a second end portion 1120. The first andsecond end portions 1115, 1120 may be angled relative to the centralportion 1110, as shown in FIG. 11 . In various embodiments of theinvention, the cannula 1100 includes a first tubing inlet 111 7 adjacentthe outer end of the first end portion 1115, and a second tubing inlet1122 adjacent the outer end of the second end portion 1020. As may beunderstood from FIG. 11 , in particular embodiments, a stop 1190 mayextend outwardly from the base portion 1105 of the cannula 1100. In someembodiments, the stop 1190 lies in between the first and second nozzles1126, 1131 and defines a central axis that runs substantially parallelto the respective central axes of the nozzles 1126, 1131. The stop 1190,in some embodiments, may extend outwardly from base portion 1105 alength greater than that of the nozzles 1126, 1131. In this manner, thestop 1190 prevents the nozzles 1126, 1131 from being inserted into theuser's nares when the cannula 1100 is in use.

For example, the stop 1190 may be positioned so that when the cannula1100 is in use, the stop is designed to engage the columella of theuser's nose and thereby prevent the nozzles 1126, 1131 from beinginserted into the user's nares. In various embodiments, the first andsecond nozzles 1126, 1131 are positioned on either side of the stop 1190so that when the cannula 1100 is operatively in use, the each nozzle1126, 1131 will be spaced apart from a respective particular one of thepatient's nares and will be positioned to direct a focused flow of gasinto that particular nare by, for example, being positioned so that theoutlet (and distal end) of each nozzle (first nozzle outlet 1183 andsecond nozzle outlet 1184) is substantially in-line (e.g., substantiallyco-axial) with, a corresponding one of the patient's nares. Similar tocannula 1000, cannula 1100 has elongate extensions 1170, 1172 that haveconduit inlets at the distal ends. Elongate extensions 1170, 1172 are ingaseous communication with conduits, such as conduit 1123.

As may be understood from FIG. 12 , in various embodiments, the cannula1200 may include only a single nozzle 1227. The nozzle 1227, in variousembodiments, has an oblong or substantially elliptical cross-section. Inthese embodiments, the major axis of the ellipse runs substantiallyparallel to the central axis of the base portion 1205 of the nasalcannula. In one embodiment, the nozzle 1227 is wide enough to allow airto flow into both of a user's nares when the nasal cannula is in use.For example, in various embodiments, the width of the nozzle 1227 (e.g.,a length defined by the major axis of the nozzle's elliptical crosssection) may be approximately equal to (or greater than) the total widthof the user's nares. In various embodiments, the cannula 1200 includes afirst tubing inlet 1217 and a second tubing inlet 1222.

As may be understood from FIG. 14 , when the nasal cannula isoperatively in use, a first lateral side 1430 of the nozzle 1429 isspaced apart from, and adjacent, a user's first nare, and a secondlateral side 1431 of the nozzle 1429 is spaced apart from, and adjacent,the user's second nare. In this and other configurations, the nozzle1429 is configured to direct a focused flow of gas simultaneously intoeach of the user's nares. In various embodiments, when the nozzle is ofa certain width, for example, approximately equal to (or greater than)the total width of the user's nares, and other widths, the nozzle 1429is sufficiently wide to prevent the nozzle 1429 from being inserted intoa user's nare, thus preventing sealing of the nasal cannula with thenare and/or is sufficiently wide to act as a stopping feature to preventthe nozzle 1429 from being inserted in the user's nares when the nasalcannula is in use. In various embodiments, first and second elongateextensions 1470, 1472 are inserted into the patient's nares. In variousembodiments, the cannula has tubing 1427 which may have multipleconduits and may be positionable around the ear(s) of the user duringuse.

In various other embodiments, the cannula's single nozzle may have adifferent cross-section that is not oblong or elliptical. For example,the nozzle may have a substantially circular cross-section, with adiameter that is wide enough to allow air to flow into both of a user'snares when the cannula is in use, while simultaneously being wide enoughto prevent insertion into a single nare. In various other embodiments,the nasal cannula may have more than one nozzle, each having asubstantially oblong cross section and a width that prevents insertioninto each of a user's nares.

In various embodiments, one or more of the cannula's elongate extensionshas a diameter that is adapted to prevent sealing with the user's nares.For example, the elongate extension(s) may have a diameter that issubstantially narrower than a user's nares, so that sealing is avoided.In other embodiments, the elongate extension(s) may include featuressuch as grooves or recesses, as described above, to prevent sealing wheninserted into a user's nare(s).

Exemplary Use of the Cannula

To use a cannula according to a particular embodiment of the invention,a physician or technician may have a patient use the cannula for a briefperiod of time, while the physician or technician monitors informationreceived from the cannula's various sensors, or the information may berecorded for later analysis. The physician or technician may then usethis information to adjust the structure or operation of the cannulauntil the cannula's sensors indicate that the patient's upper airwayenvironment satisfies certain conditions.

Similarly, in various embodiments, the cannula's sensors may be used tomonitor conditions within the patient's upper airway over time. In aparticular embodiment, the cannula's sensors may be connected to acontrol system that will automatically alter or modify the flow oftherapeutic gas into the cannula if information from the sensorindicates undesirable conditions within the patient's upper airway. Infurther embodiments of the invention, the sensor is connected to acontrol system that issues an alarm if information from the cannula'ssensors indicates undesirable conditions within the patient's airway.

FIGS. 13 and 14 depict various embodiments of nasal cannulas being usedon a patient. As may be understood from FIG. 13 , for example, a nasalcannula is used on a young or small infant for high flow therapy. Forexample, a nasal cannula similar to that shown in FIG. 10 can be used.In various embodiments, first and second elongate extensions 1370, 1372are inserted into the patient's nares, while corresponding first andsecond nozzles 1326, 1331 remain adjacent and external to the patient'snares. As may be appreciated, when the nasal cannula is in use, airflows into the patient's nares via the nozzles. FIG. 14 depicts oneembodiment of a nasal cannula in use on a patient. In one embodiment, anasal cannula such as that shown in FIG. 12 can be used. As may beunderstood from FIG. 14 , a nasal cannula having a single nozzle 1429can be used, in which the nozzle is sized and shaped (e.g., iselliptical and/or wider than a patient's nare) to prevent insertion intothe patient's nares. In various other embodiments, nasal cannula havingnasal insert type nozzles, as described throughout, can be used. Inthese embodiments, the nasal inserts are inserted into the user's nareswhile the cannula is in use. Nasal cannula according to embodiments ofthe invention can be used on a variety of patients.

High Flow Therapy Device

Now referring to FIGS. 15-17 , a high flow therapy device 2000 is shown.High flow therapy device 2000 is configured for use with a nonsealingrespiratory interface, such as cannula 10, for example, to deliver gasto a patient. In various embodiments, high flow therapy device 2000 isable to heat, humidify, and/or oxygenate a gas prior to delivering thegas to a patient. Additionally, embodiments of high flow therapy device2000 are able to control and/or adjust the temperature of the gas, thehumidity of the gas, the amount of oxygen in the gas, the flow rate ofthe gas and/or the volume of the gas delivered to the patient.

High flow therapy device 2000 is shown in FIG. 15 including a housing2010, a humidity chamber 2020 (e.g., vapor generator), a user interface2030, a gas inlet port 2040 and a gas outlet port 2050. A microprocessor2060, an air inlet port 2070, a blower 2080, an oxygen inlet 2090 and aproportion valve 2100 are illustrated in FIG. 16 . A non-sealingrespiratory interface (such as a cannula illustrated in FIGS. 1-14(e.g., 10 or 1200), hereinafter referred to as 100, is configured tomechanically cooperate with gas outlet port 2050 to supply a patientwith gas. The user interface 2030 includes a user display that isadapted to display data as a graph. The data can include, but is notlimited to, pressure, amount of oxygen in the gas, the flow rate of thegas and/or the volume of the gas delivered to the patient. Asillustrated in FIG. 15 , the display of user interface 2030 can bepositioned at an angle relative to the housing 2010 and/or a top surfaceof the housing 2010.

A heating element 2110 is shown schematically in FIG. 17 (and is hiddenfrom view by humidity chamber 2020 in FIG. 15 ) is in electricalcommunication with microprocessor 2060 (which is included on printedcircuit board (“PCB”)), via wire 2112, for instance, and is capable ofheating a liquid (e.g., water) within humidity chamber 2020 to create agas. Non-sealing respiratory interface 100 is configured to deliverythis gas to a patient. Further, a sensor 2120 or transducer (shown inFIG. 20 ) is disposed in electrical communication with microprocessor2060 and is configured to measure pressure in the upper airway UA(including both the nasal cavity and the oral cavity) of a patient. Inan embodiment, a sensor conduit 2130 extends between the upper airway ofthe patient and sensor 2120 (FIG. 19 , sensor 2120 is not explicitlyshown in FIG. 19 , but may be disposed adjacent microprocessor 2060). Inanother embodiment, sensor 2120 is disposed at least partially withinthe upper airway of the patient with a wire 2122 relaying signals tomicroprocessor 2060 (FIGS. 18 and 20 ).

In use, a liquid (e.g., water) is inserted into humidity chamber 2020through a chamber port 2022, for instance. Heating element 2110 heatsthe liquid to create a vapor or gas. This vapor heats and humidifies thegas entering humidity chamber 2020 through gas inlet port 2040. Theheated and humidified vapor flows through gas outlet port 2050 andthrough non-sealing respiratory interface 100.

In a disclosed embodiment, sensor 2120 collects data for the measurementof the patient's respiration rate, tidal volume and minute volume.Further, based on measurements taken by sensor 2120 and relayed tomicroprocessor 2060, microprocessor 2060 is able to adjust thetemperature of the gas, the humidity of the gas, the amount of oxygen ofthe gas, flow rate of the gas and/or the volume of the gas delivered tothe patient. For example, if the pressure at the patient's upper airwayis measured and determined to be too low (e.g., by a pre-programmedalgorithm embedded on microprocessor 2060 or from a setting inputted bya operator), microprocessor 2060 may, for example, adjust the speed ofblower 2080 and/or oxygen proportional valve 2100 so that sufficientpressure levels are maintained.

Additionally, sensor 2120 may be used to monitor respiratory rates, andmicroprocessor 2060 may signal alarms if the respiratory rate exceeds orfalls below a range determined by either microprocessor 2060 or set byan operator. For example, a high respiratory rate alarm may alert theoperator and may indicate that the patient requires a higher flow rateand/or higher oxygen flow.

With reference to FIG. 17 , a pair of thermocouples 2200 and 2202 isillustrated, which detect the temperature entering and leaving a circuit2210 disposed between non-sealing respiratory interface 100 and gasoutlet port 2050. Further, a second heating element 2114 (or heater)(e.g., a heated wire) may be disposed adjacent air outlet port 2050 tofurther heat the gas. It is also envisioned that second heating element2114 is disposed within circuit 2210. Thermocouples 2200 and 2202 are incommunication with microprocessor 2060 and may be used to adjust thetemperature of heating element 2110 and second heating element 2114. Afeedback loop may be used to control the temperature of the deliveredgas, as well as to control its humidity and to minimize rainout. FIG. 16illustrates an embodiment of circuit 2210 including sensor conduit 2130co-axially disposed therein, in accordance with an embodiment of thepresent disclosure.

Relating to the embodiment illustrated in FIG. 16 , blower 2080 is usedto draw in ambient air from air inlet port 2070 and force it through anair flow tube 2140, through gas inlet port 2040, through humiditychamber 2020 and through gas outlet port 2050 towards non-sealingrespiratory interface 100. Blower 2080 is configured to provide apatient (e.g., an adult patient) with a gas flow rate of up to about 60liters per minute. In a particular embodiment, it is envisioned thatblower 2080 is configured to provide a patient with a gas flow rate ofup to about 40 liters per minute. Additionally, an air intake filter2072 (shown schematically in FIG. 17 ) may be provided adjacent airinlet port 2070 to filter the ambient air being delivered to thepatient. It is envisioned that air intake filter 2072 is configured toreduce the amount of particulates (including dust, pollen, fungi(including yeast, mold, spores, etc.) bacteria, viruses, allergenicmaterial and/or pathogens) received by blower 2080. Additionally, theuse of blower 2080 may obviate the need for utilization of compressedair, for instance. It is also envisioned that a pressure sensor isdisposed adjacent air intake filter 2072 (shown schematically in FIG. 17), which may be capable of determining when air intake filter 2072should be replaced (e.g., it is dirty, it is allowing negative pressure,etc).

With continued reference to FIG. 16 , oxygen inlet 2090 and isconfigured to connect to an external source of oxygen (or other gas)(not explicitly shown) to allow oxygen to pass through high flow therapydevice 2000 and mix with ambient air, for instance. Proportion valve2100, being in electrical communication with microprocessor 2060, isdisposed adjacent oxygen inlet 2090 and is configured to adjust theamount of oxygen that flows from oxygen inlet 2090 through an oxygenflow tube 2150. As shown in FIGS. 16 and 17 , oxygen flowing throughoxygen flow tube 2150 mixes with ambient air (or filtered air) flowingthrough air flow tube 2140 in a mixing area 2155 prior to enteringhumidity chamber 2020.

In a disclosed embodiment, sensor 2120 measures both inspirationpressure and expiration pressure of the patient. In the embodimentillustrated in FIGS. 18 and 19 , sensor conduit 2130 delivers thepressure measurements to sensor 2120 (not explicitly shown in FIGS. 18and 19 ), which may be disposed adjacent microprocessor 2060. In theembodiment illustrated in FIG. 20 , sensor 2120 is position adjacent thepatient's upper airway and includes wire 2122 to transmit the readingsto microprocessor 2060.

In various instances, clinicians do not desire ambient air to enter apatient's upper airway. To determine if ambient air is entering apatient's upper airway (air entrainment), the inspiration and expirationpressure readings from within (or adjacent) the upper airway may becompared to ambient air pressure. That is, a patient may be inhaling gasat a faster rate than the rate of gas that high flow therapy device 2000is delivering to the patient. In such a circumstance (since non-sealingrespiratory interface 100 is non-sealing), in addition to breathing inthe supplied gas, the patient also inhales ambient air. Based on thisinformation, microprocessor 2060 of high flow therapy device 2000 isable to adjust various flow parameters, such as increasing the flowrate, to minimize or eliminate the entrainment of ambient air.

FIG. 21 illustrates an example of a screen shot, which may be displayedon a display portion of user interface 2030. The crest of the sine-likewave represents expiration pressure and the valley representsinspiration pressure. In this situation, ambient air entrainment intothe patient's upper airway is occurring as evidenced by the valley ofthe sine wave dipping below the zero-pressure line. Microprocessor 2060may be configured to automatically adjust an aspect (e.g., increasingthe flow rate) of the gas being supplied to the patient by high flowtherapy device 2000 to overcome the entrainment of ambient air. Further,microprocessor 2060 may convey the pressure readings to the operator whomay then input settings to adjust the flow rate to minimize entrainmentof ambient air or to maintain a level of pressure above the ambient airpressure. Further, lowering the flow rates during expiration may alsominimize oxygen flow through high flow therapy device 2000. Suchlowering of a flow rate may also minimize entry of oxygen into a closedenvironment, such as the patient room or the interior of an ambulance,where high levels of oxygen might be hazardous.

In a disclosed embodiment, sensor conduit 2130 may be used as a gasanalyzer, which may be configured to take various measurements (e.g.,percent of oxygen, percentage of carbon dioxide, pressure, temperature,etc.) of air in or adjacent a patient's upper airway.

In another embodiment (not explicitly illustrated), a gas port may bedisposed adjacent housing 2010 to communicate with exterior of housing2010. It is envisioned that the gas port is configured to allow the useof external devices to measure various gas properties (e.g., percentoxygen and pressure). Additionally, the gas port may be used forexternal verification of gas values. Further, a communications port2300, shown in FIG. 16 , may be included to facilitate connection withan external device, such as a computer, for additional analysis, forinstance. Further, communications port 2300 enables connection withanother device, enabling data to be monitored distantly, recorded and/orreprogrammed, for example.

A directional valve 2160 and/or a sample pump 2170 (schematically shownin FIG. 17 ) may also be included to facilitate sampling the gas foranalysis. More specifically, in a particular embodiment, sample pump2170 is capable of moving a quantity of gas towards the gas analyzer. Asshown schematically in FIG. 17 , the gas sample can be taken from apatient's upper airway via sensor conduit 2130 or from mixing area 2155via a sample line 2180 and a sample port 2182 (FIG. 16 ). Directionalvalve 2160 may be controlled by microprocessor 2060 to direct a gassample from either location (or a different location such as after thegas is heated). The gas analyzer can compare measurements of the gassample(s) with predetermined measurements to ensure high flow therapydevice 2000 is working optimally. It is further envisioned that samplepump 2170 may be configured to pump a gas or liquid towards the patientto provide the patient with an additional gas, such as an anesthetic,for instance and/or to clean or purge sensor conduit 2130.

The present disclosure also relates to methods of supplying a patientwith gas. The method includes providing high flow therapy device 2000,as described above, for example, heating the gas, and delivering the gasto the patient. In this embodiment, high flow therapy device 2000includes microprocessor 2060, heating element 2110 disposed inelectrical communication with microprocessor 2060, non-sealingrespiratory interface 100 configured to deliver gas to the patient andsensor 2120 disposed in electrical communication with microprocessor2060 and configured to measure pressure in the upper airway of thepatient. The method of this embodiment may be used, for instance, toprovide a patient with respiratory assistance. Blower 2080 may also beincluded in high flow therapy device 2000 of this method. Blower 2080enables ambient air to enter high flow therapy device 2000 (e.g.,through filter 2072) and be supplied to the patient. In such anembodiment, high flow therapy device is portable, as it does not need anexternal source of compressed air, for example.

Another method of the present disclosure relates to minimizingrespiratory infections of a patient. In an embodiment of this method,high flow therapy device 2000 includes heating element 2110 andnon-sealing respiratory interface 100. Here, a patient may be providedwith heated and/or humidified air (e.g., at varying flow rates) to helpminimize respiratory infections of the patient. Further, such a methodmay be used in connection with certain filters 2072 to help preventpatients from obtaining various conditions associated with inhalingcontaminated air, such as in a hospital. Additionally, providingappropriately warmed and humidified respiratory gases optimizes themotion of the cilia that line the respiratory passages from the anteriorthird of the nose to the beginning of the respiratory bronchioles,further minimizing risk of infection. Further, supplemental oxygen mayadd to this effect. Microprocessor 2060 in connection with sensor 2120may also be included with high flow therapy device 2000 of this methodfor measuring and controlling various aspects of the gas being deliveredto the patient, for instance, as described above.

A further method of the present disclosure relates to another way ofsupplying a patient with gas. The present method includes providing highflow therapy device 2000 including heating element 2110, non-sealingrespiratory interface 100, blower 2080, air inlet port 2070 configuredto enable ambient air to flow towards blower 2080 and filter 2070disposed in mechanical cooperation with air inlet port 2070 andconfigured to remove pathogens from the ambient air. High flow therapydevice 2000 of this method may also include microprocessor 2060 andsensor 2120.

Another method of the present disclosure includes the use of high flowtherapy device 2000 to treat headaches, upper airway resistancesyndrome, obstructive sleep apnea, hypopnea and/or snoring. High flowtherapy device 2000 may be set to provide sufficient airway pressure tominimize the collapse of the upper airway during inspiration, especiallywhile the use is asleep. HFT may be more acceptable to children andother who may not tolerate traditional CPAP therapy, which requires asealing interface. Early treatment with HFT may prevent the progressionof mild upper airway resistance syndrome to more advanced conditionssuch as sleep apnea and its associated morbidity.

Another method of the present disclosure is the treatment of headachesusing HFT. In an embodiment of treating/preventing headaches, gas may bedelivered to patient at a temperature of between about 32.degree. C. andabout 40.degree. C. (temperature in the higher end of this range mayprovide a more rapid response) and having at least about 27 milligramsof water vapor per liter. More specifically, it is envisioned that a gashaving a water vapor content of between about 33 mg/liter and about 44mg/liter may be used. It is envisioned that the gas being delivered tothe patient includes moisture content that is similar to that of atypical exhaled breath. In an embodiment, the flow rates of this heatedand humidified air are sufficient to prevent/minimize entrainment ofambient air into the respired gas during inspiration, as discussedabove. The inclusion of an increased percentage of oxygen may also behelpful. Further, the gas may be delivered to the patient usingnon-sealing respiratory interface 100.

High flow therapy device 2000 used in these methods includes heatingelement 2110 and non-sealing respiratory interface 100. Microprocessor2060 and sensor 2120 may also be included in high flow therapy device2000 of this method. The inclusion of blower 2080, in accordance with adisclosed embodiment, enables high flow therapy device 2000 to beportable, as it does not need to be connected to an external source ofcompressed air or oxygen. Thus, high flow therapy device 2000 of thismethod is able to be used, relatively easily, in a person's home, adoctor's office, an ambulance, etc.

The present disclosure also relates to a method of deliveringrespiratory gas to a patient and includes monitoring the respiratoryphase of the patient. Monitoring of a patient's respiratory phase isenabled by taking measurements of pressure in a patient's upper airway.Additionally, respiratory phase may be determined by pressure withcircuit 2210 or by monitoring activity of the phrenic nerve. Real-timepressure measurements (see sine-like wave in FIG. 21 , for example)enable real-time supplying of gas at different pressures to be deliveredto the patient, or variable pressure delivery. For example, gas at ahigher pressure may be delivered to the patient during inspiration andgas at a lower pressure may be delivered to the patient duringexpiration. This example may be useful when a patient is weak and hasdifficultly exhaling against an incoming gas at a high pressure. It isfurther envisioned that the pressure level of the gas being delivered toa patient is gradually increased (e.g., over several minutes) to improvepatient comfort, for instance.

With reference to FIGS. 22-24 , mouthpiece 3000 is illustrated inaccordance with an embodiment of the present disclosure. As brieflydescribed above, mouthpiece 3000 is an example of a respiratoryinterface of the present disclosure. Mouthpiece 3000 (illustratedresembling a pacifier) may be used to detect upper airway pressure of apatient.

A first mouthpiece port 3010 may be used to measure pressure insidemouthpiece 3000 through open end 3012 of first port. First mouthpieceport 3010 may include an open-ended tube that communicates the pressurewith mouthpiece 3000 to sensor 2120 (not explicitly shown in FIGS. 22-24) via first port conduit 2130 a. Sensor 2120 may also be positionedwithin mouthpiece 3000. It is envisioned that mouthpiece 3000 is atleast partially filled with a gas or liquid, e.g., water.

The pressure within mouthpiece 3000 may help evaluate, record orotherwise use the pressure data for determining the strength of suckingor feeding, for instance. The timing of the sucking motion and thedifferential pressures in the mouth may also be measured. The suckingpressure may be used to help determine the strength of the sucking andmay be used to evaluate the health of an infant, for instance. Themeasurement of oral-pharyngeal pressure may also give data for settingor adjusting respiratory support therapy for the patient. It isenvisioned that a relatively short first mouthpiece port 3010 may beused so that a bulb 3030 of mouthpiece 3000 acts as a pressure balloon.It is also envisioned that a relatively long first mouthpiece port 3010having rigidity may be used to help prevent closure of the tube frompressure from alveolar ridges or from teeth, for example.

A second mouthpiece port 3020 is configured to enter a patient's mouthor oral cavity when mouthpiece 3000 is in use and is configured tomeasure pressure within the oral cavity (upper airway pressure) throughan open end 3022 of second mouthpiece port 3020. Pressure from withinthe upper airway (e.g., measured adjacent the pharynx) may betransmitted to sensor 2120 via second port conduit 2130 b or sensor 2120may be positioned adjacent mouthpiece 3000. That is, the pressurecommunicated from with the upper airway to the patient's mouth is thepressure being measured. It is envisioned that second mouthpiece port3020 extends beyond a tip of bulb 3030 to facilitate the acquisition ofan accurate upper airway pressure measurement.

Referring to FIG. 23 , a balloon 3040 is shown adjacent a distal end3024 of second port 3020. Here, it is envisioned that a lumen of conduit2130 b is in fluid communication with the internal area of balloon 3040.Further, any forces against a wall of balloon 3040 are transmittedthrough the lumen towards sensor 2120 or transducer for control,observation or analysis.

The pressure within the oral cavity may vary during the phases ofsucking and swallowing. High flow therapy device 2000 using mouthpiece3000 enables concurrent measurement of sucking pressure withinmouthpiece 3000 and the pressure outside mouthpiece 3000. This data mayhelp determine treatment characteristics for respiratory support forinfants, children or adults, e.g., unconscious adults.

CONCLUSION

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims. Forexample, although the embodiment shown in FIG. 1 shows each nozzle 125,130 having a two conduit inlets 152, 154, in alternative embodiments ofthe invention, one or more of the nozzles 125, 130 may have more or lessthan two conduit inlets (and/or more or less than two sensors). Further,sensor 2120 may be situated or in communication with any area of theairway, and is not limited to sensing the environment of the anteriornares. Although specific terms are employed herein, they are used in ageneric and descriptive sense only and not for purposes of limitation.

1-20. (canceled)
 21. A high flow therapy system, comprising: a housing;an air inlet formed in the housing to receive ambient air; a gas inletport configured to be connected to an external source of gas; arespiratory gas flow pathway extending from within the housing andconfigured to deliver a respiratory gas to a non-sealing nasalinterface, wherein the respiratory gas flow pathway includes a blowercontained within the housing that is configured to generate apressurized flow of the respiratory gas, wherein the housing furthercontains a microprocessor that is configured to control the blower toadjust a flow rate of the respiratory gas, wherein the blower isconfigured to generate and the microprocessor is configured to controlthe flow rates of the respiratory gas of up to 60 liters per minute toprovide high flow therapy to the non-sealing nasal interface; a mixingarea contained within the housing for mixing the ambient air and the gasin the respiratory gas flow pathway so that the respiratory gascomprises a mixture of the air and the gas; a humidification areadownstream of the mixing area that includes a humidity chamberconfigured to contain a volume of water and a first heating elementconfigured to heat the water, wherein the first heating element iscontrolled by the microprocessor, wherein the humidification area isconfigured to provide the respiratory gas with added humidification inthe respiratory gas flow pathway; and a heated delivery conduitconfigured to convey the respiratory gas with added humidification tothe non-sealing nasal interface, wherein the heated delivery conduitincludes a second heating element that is controlled by themicroprocessor.
 22. The high flow therapy system of claim 21, wherein atleast one of respiration rate, tidal volume and minute volume arecalculated by the microprocessor.
 23. The high flow therapy system ofclaim 21, wherein the microprocessor is configured to control at leastone of the temperature of the respiratory gas, the humidity of therespiratory gas, the mixture of the respiratory gas, the flow rate ofthe respiratory gas, and the volume of the respiratory gas deliverableto the non-sealing nasal interface.
 24. The high flow therapy system ofclaim 23, wherein the microprocessor is configured to adjust the flowrate based on at least one of a pre-programmed algorithm and a settinginputted by an operator.
 25. The high flow therapy system of claim 23,further comprising a user interface that outputs an alarm when a sensedcondition deviates from pre-determined criteria.
 26. The high flowtherapy system of claim 23, wherein the system is configured to controlthe flow rate of the respiratory gas delivered to the patient based on arespiratory phase of a patient.
 27. The high flow therapy system ofclaim 21, wherein the system is configured to deliver the respiratorygas to the patient at different airway pressures based on a respiratoryphase of a patient.
 28. The high flow therapy system of claim 21,further comprising a gas analyzer contained within the housing, whereinthe microprocessor is communicatively coupled to the gas analyzer andconfigured to control, at least, the flow rate of the respiratory gasbased on signals received from the gas analyzer.
 29. The high flowtherapy system of claim 21, further comprising a user interface displaypositioned along the housing and controlled by the microprocessor. 30.The high flow therapy system of claim 21, further comprising aproportional valve positioned within the housing.
 31. The high flowtherapy system of claim 21, further comprising the non-sealing nasalinterface.
 32. The high flow therapy system of claim 31, wherein thenon-sealing nasal interface includes a nasal cannula.
 33. The high flowtherapy system of claim 32, further comprising a sensor for monitoringan airway parameter, wherein the microprocessor is configured to respondto the sensor communicating a signal indicative of the airway parameter.34. The high flow therapy system of claim 33, wherein the sensor isconfigured to measure at least one of inspiration pressure andexpiration pressure.
 35. The high flow therapy system of claim 33,wherein the sensor is at least partially positioned within therespiratory gas flow pathway.
 36. The high flow therapy system of claim21, wherein: the heated delivery conduit further includes a thermocouplethat is configured to measure a temperature of the respiratory gas withadded humidification within the heated delivery conduit, and themicroprocessor is further configured to receive the measured temperaturefrom the thermocouple and to control delivery of the high flow therapybased, at least in part, on the measured temperature.
 37. The high flowtherapy system of claim 36, wherein the microprocessor controllingdelivery of the high flow therapy comprises controlling the firstheating element.
 38. The high flow therapy system of claim 36, whereinthe microprocessor controlling delivery of the high flow therapycomprises controlling the second heating element, and wherein the secondheating element is configured to reduce condensation within the heateddelivery conduit.
 39. The high flow therapy system of claim 21, whereinthe gas comprises oxygen and the external source comprises an externalsource of the oxygen.
 40. The high flow therapy system of claim 21,further comprising: means for sensing conditions of the respiratory gas,wherein the microprocessor is configured to control the high flowtherapy based on the sensed conditions.